This invention generally relates to pumps with impellers and in particular to an integrated elastomeric seal impeller and boot for use in a pump.
Water pumps with impellers are used in appliances, such as dishwashers and washing machines, to move liquid through and out of the appliance in a series of wash, rinse, and drain cycles. Typically, the pump includes a housing, a rigid cover, and an elastomeric impeller molded around a rigid impeller insert for slip fitting onto a rotatable drive shaft or motor shaft. A separate mechanical face seal assembly consisting of a seal head assembly and a seal seat for preventing liquid leakage between the fixed housing and the rotating impeller, and a two-piece thrust bearing, one half mounted in the impeller for running against the other half mounted in the rigid cover, are used. This thrust bearing resists the axial force of the mechanical face seal and also establishes the axial running clearances of the impeller with both the housing and the rigid cover.
The assembly of all these separate components can lead to mis-assembly and damage to critical sealing components. Some prior art pumps have used some pre-assembly of components to reduce handling and assembly time. However, these prior art pumps have not been widely adopted because of the cost of the additional pre-assembly.
Thus, there is a need to solve these problems and to provide a simple, more cost effective combination of a mechanical face seal boot and a pump impeller which integrates the boot with the impeller so that the biasing spring and seal seat are disposed within the pump impeller, thereby protecting these components from damage or contamination and reducing the number components, reducing cost, and reducing assembly time.
The present invention seeks to solve these problems by providing an integrated boot, seal and impeller system for use in a pump.
The present invention is directed to an integrated boot, seal and impeller system that is adapted for pumping fluid by a power shift. The system includes an impeller unit having a plurality of radially extending blades, a hub portion, a recess in the hub portion and a tubular portion extending from the hub portion. The tubular portion is engaged to the shaft and has an outer diameter with at least one flat in the outer diameter. A seal head is slidingly engaged to the tubular portion. The seal head also has an inner diameter with at least one flat on the inner diameter to engage the outer diameter of the tubular portion. A flexible boot extends from the elastomeric blades. The boot has a distal portion adjacent to the seal head. Additionally, a biasing member is disposed in the recess and urges the seal head into engagement with the seal washer.
It is an object of the present invention to provide an integrated boot, seal and impeller system for use in a water pump to protect the components from damage during the assembly process.
It is another object of the present invention to provide a simpler, more cost effective boot, seal and impeller construction which integrates the boot and impeller to reduce the number of components required and reduce assembly time. The present invention provides an integrated boot, seal and impeller. construction that is simpler and more cost effective, and which allows for pre-testing of the integrated boot, seal and impeller assembly for leakage prior to installation to the pump.
Still another object of the present invention is the elimination of the separate molding of a protective boot for the seal components thereby allowing for a simpler assembly of the seal for use in a pump.